Explosive device



Oct. 28', 1958 F. R. sEAVEY EXPLQSIVE DEVICE Filed Sept. 29. 1 954FREDERICK R. SEAVEY AGENT .Thisfinventionrelates enerally'to explosivesandmore particularly tote a1 ynovel; xp1os`io-retarding coupler forlengths: ofdetonating fuse; 'fl

4Itifisdesirabler-in some fblastin inquarr-ies :and: in; someigsrface-mines to shoot successively severalv explosive charges `which have beenproperly spaced `oven an areato' beffblastedwithoutfitbeingnecessal-'yfioimpersonnel?y onation sof; f thes places, ein :the areadetonating fusejplacedinvthe drillhole withhthe vexplosive charge.l*andi extending to; afcomnion trunk line 'of ysimilar` detonatingafuse" g operations particularly to enterithe area .between shots; Det-`explosive chargesilocateld i fat" various iseaccomplished byineansv of`lengths of` i ing i *lengths of detonating Afuse 'and for f'retiardingthe` initiation' of the second "length of idetonating fuse which doesnot req'uirelprecise assembly With' theifuse Ltofbe blasfugij A CHv-detonating'fus ,Y .E .t i 1 Figure `2` illustrates,`"1n` afragilientaryside view, "partiallyl.

another embodiment ofzthe inventionhaving a Abeit-.SafelyV initiated."-rv'The simultaneous Eexplosion of. all 'l thegchages is undesirablefbecause of the 'degree v ofearth Y vibration produced: 'thereby-sox`it] is desirable to `providedelayifelementshor,xeXplosionfretardinglf.devices between the-lengthsofdetonating'rfuse feitherlin each branch lineor,;-ativariousipoints`tin f the Ytrunk linev in order to :lire `the explosive f.ch`argesfsuccessively. uf One such? device Vwhich I has;` :been `proposed ifforifthis I purpose fhas ia deiag'r-ating charge butted up against onelength-of'detonatingfuse and: aniigition mixture buttedup 1against thefother length ofsdetonating fuse zwith af :delay c between. In this type.f"dvicethe`naine-fromme `rst length of :fusewignites the lignitionmixture 'which' in` turn charge l interposed `thereifgnites1the-delyfcompositionandithe deilagrating charge. Ithas:been-''found` in'iprctice, '.howeve'rl; that such 5a` devicedepending;` uponezthe'fflamef of ther burning detonating', fuse iforiignitic'ins Vis not entirelyasatisfactory\'because Vityfrequently:ifails i toc-ignite:r the i second i length of detonating f fuse.;Inforder tofins'ure ignitionof the rsecond length,

assemblyrisinot always :obtained in practice Moreover,considerable:diiiicultyfliasfbeen experienced in' c Which mightAbe-"atzsleast partially.` responsible for `'the ignitionA failures.

makingrsucli ai device'scientlywaterproof for use atmanyxblastiiigsitesisoit has beenznecessary for `the manu# facturenftovspply andevicel having short lengths i Vof `detsure waterproofness Al y containing `both =anfiinitiatingachargeandv thej quantity ofsecondary;explosivesvfinfthesefsocalled Vfuse tails. `Itvisfthe'reforei`anfzbject fof invention to provide a t is undesirable to shipv packagesadvantages; fzfAnotl'neri'object ofthisf-'invention is toprovidel;anaexplosionfretarding vand'ficonnecting` means-for ir'nprovedfunctioning.y i charac ristics. ,fujrtlier objectwofthis;'inventionistoc osiye device adaptedqtobe ,interposed belength of ydetonating fusefhavin vice g v,with l the fr Ordinarily, in practicing o Y, facilitatelassembly' j 7of fthe @various components fof the 2.o,V device, it 'ispreferred to *make the/ explosin Vretaitding explosivechargeandaconventionalv det-V.,l

i of cyclonite 1" yare operative f o and which libe toV the tradevwithout detonating fuse'f 'attached `tl:n=.'retc` Theforegoingobjectsfas' wellfas thesiwill become",

apparent* from i 'the followingf description 'reference' to theaccompanying drawing invvliich:v Figure l illustrates, one embodiment ofthis inV section, o c different type `of, centeriire percussion typeprimer;`

Figure `-3 illustrates, in a fragmentaryside view, partially` 'iin-section, anotheremb rimr'e primer; and" Figure 4 illustrates, inafragimentary side View, partialliy` 1n section anotherembodimentofztheinvention having all',

stab'intiated type primer.'

ona'ting `fuse having an' explosio includes a'percussion' type ignitionassembly. Preferably, the invention provides `ahtulpuvllar` couplingd'eviceltforI "detf` onating fuse which contains" anlexplosion-rtardinghelement'having apercssion ignitionlassemblyadjacentfone,"k

adjacent the fother'end deronating'c'hargc and a delay' means'interpo'se-d` 'between'- the and` detonating charge.'

element by pressingthe' etongatirlg a suitable delay composition chargefin openl and havingv a ,perforat after'close the open endofthe'"detonatrVcaselbyA insertlingY aconventional shotgun cartridge'priiner assembly.

Such an` assembly of 'battery cup," anvil fand-primerl cup containinga'suitablev4 composition is ideally suited'` for the purpose 'because o othe delay compositionlbuti't also'ha it is insertedinthedetonatjsrcase.`

lacquer or other sealing"material,

positioned within thentulbe Aaiij'acent'o.thatc endof theas f semblyhaving the' jpercussion primer and-indental o in'thetube `vvz`1ll`n=l.far eachend of the tuber-,1 to stop the detonatingffuse`whenwit isla'ter insertedin.- l

tions are placed the tube; o v ,v

In order vfurther `to is a description of one to the accompanyingdrawing: .t v

In the embodiment ,shown hin Figure V1.,.aboutl3 grains,. .pressednin.aY2conventional aluminum -p detonator'case Z'underfa loadof about 80poundsV dead` Weight. Immediately;Hanovre.v .,theg cyclonite`(cyclotri-- methylenetrinitramine) ,1,I `separate j charges` 4lofA iabout ^521/2 ig; V

grains of lead azide.'V 3, abontly/zgrain oileadfstyphnateA composed,lof aboutrv p rngethallicl lead", powder, `about 25 selenium` powderyYabout` .4% potassium-o chlorate and i Y; about 5 Z1 barium, nitrate areeach pressed underrsimilar a pressures.` An'aluniinumjerrule having acentral per- `foration l7 in the bottom thereof and of such diameter `rn'a Y iongifudiai `'sectional viewgf invention attached Ito` lengths l.of

odirnent offtlie inverition".liavingafv Generally speaking, the' objectsi of this.: 'invention i' are accomplished by providing acoupler forlengths of `dettarding elementwhich vention; in.` order V tojv y c c o lo o 4ottominside the'detonatoij"f1-` case` and adjacent the delay.composition, @and toftheie.- l

it isv not., onlycap'ablc of` AignitingI I imensions such Vthat ,1. 1tcan be'readily assembled Vv'v`itl4,aconventional "detonator `case.'``order` to Ainsureltliat no moisture can Venterotlziis. i. assembly, itis rvpreferredtola'cqueor. thebattery cupbefore, t A 'JAftelr insertionof the primer, the entire assemblyI iisldlpped vassuitable a n `Theresulting assembly is then yplracedjin Valsuitableitubefadapterl,totQ*overV they a' rinspin .'srroperly ithe@andererepentir? mbodirnent thereof withreference g as to form aslidableitincase is placed over the delay composition and a shotshellprimer designated generally by the numeral 8 composed of a battery cup9, primer cup 10 containing priming mix 11 and anvil 12 is inserted inthe I11,Q11fh0f y the. detonator case2. This shotshell primer 8.is.dipped,`infalnitrocellulose lacquer which is permitted to dry before it isinserted in thedetonator case 2. After primer 8.has been properlypositioned in the mouth of the detonator case 2, the mouth of the entireassembly is dippedin the nitrocellulose lacquer to insurewaterproofness. v'The length of aluminum ferrule 6 is predetermined inorder to insure thatthe detonator 2 is completely, iilled with thevarious components placed therein.

The assembled detonator is positioned in aluminum tube 13 suchA thattheend containing-charge 1 is' about '/s1inch ,fromonmend of they about41/2 inches long tube 13 havingan outside` diameter `of-about 0.27 inch.An annular ring 14 isjformedv in the tube wall to ksecure theassembled-detonator inplace. Firingv pin 15 is positioned about 1A; inchfrom primer cup 10 and two or more indentations 16. are formed inthetube wall to lock the tiring pin in place. Annular ring 17 is formed inthe tube wall to be used later by the operator to predetermine theproper distance to whichV detonating fuse 18 should be inserted.

In operation, one length of detonating fuse 18 is inserted until the endthereof abuts against annular ring 17 and annular crimp26` is formed inthe wall to secure detonating fuse 18 within the assembly. A secondlength of detonating fuse 19 is inserted in the other end of tube 13 andin contact with the base of case 2. Annular ring 20 is formed in theWall of tube 13 to secure fuse 19 in position. Upon detonation of thefuse 18 gases accumulate in the space 21 behind tiring pin 15 and whensuiii y cient pressure has been developed to break the lock provided byindentations 16, firing pin 15 is driven into primer vcup 10,compressing priming mix 11 between anvil 12 and the wallV of primer cup10. Delay mix 5 is thus ignited and after the predetermined timeinterval afforded thereby, in this particular embodiment about 0.05second, the explosive charges 4, 3 and 1 are initiated with subsequentinitiation of detonating Afuse 19.

In the embodimentshown in Figure2 a tube 13 similar to that in theembodiment of Figure 1 is provided with a firing pin 15 secured in placeby means of indentations 16 in the Wall of the tube 13. Spacedabout 1A;inch from the striking point of firing pin.15-is aconventionalcenterfire primer such as used in rie and pistol cartridges anddesignated generallyk in` the drawing` as numeral 80. Primer 80 iscomposed vof primer cup 100v containing primingmix 111 and anvil`121which rests against the end of ferrule 6. Primer assembly Sil-andferrule 6 are shown enclosed in Adetonator case 2. Annular indentations14 secure the assembled detonator in place in tube 13.- Priming mix 111may be any suitable priming mix used in rifle and pistol cartridges.

In the rimire type embodiment illustrated inFigure 3, tube 13 contains aproperly positioned ring pin 252 having an annular protuberancev 24designed to be driven against the rimre cap 200 containing priming mix211. Cap 200 may be provided with an annular ange similar to thatutilized in` rimire rifle and pistol cartridges as an extraction angeand this ilange may extend over the mouth of detonator 2 in order to aidin water-proofing the detonator assembly. Themouth of cap 200 is buttedagainst the open end of ferrule 6 and the 4entire assembly withindetonator case 2 is such that cap 200 is rigidly supported in order toinsure that priming mix 211 will be initiated when struck by firing pin252.

In Vthe embodiment of Figure 4 illustrating a primer of thestab-initiated type, a detonator case 2 is charged with a base charge ofsuitable explosives such as cyclonite 1, and an initiating rcharge oflead azide 3, a delay composition Sand a primer 311. This explosivetrain is enclosed withinY detonator case 2 by placing a suitable washr 22,

. such as one cut from aluminum foil, in the mouth of case 2 andthereafter turning the end of the case 2.ove11fthev washer 22 to secureit in place. Slidable firing pin 15 is provided with a pointedprotuberance 23 and is properly positioned in tube 13 by means of crimp16. The gases developed by the detonation of the length of detonatingfuse back of the firing pin 15 drive the ring pin into contact withdetonator case 2 forcing protuberance 23 into mouth 27 of case 2 andthrough washer 22 into primer 311. The primer is initiated by thepenetration.- of protuberance 23 and ignites delay mix 5 which in turnignites the initiator charge 3 and base chargevl.'` In some embodimentsof this type, a ferrule 6, such as illustrated in Figure l, may beplaced between theA primer- 311V and delay mix 5. Washer 22 can be madefrom other metal foils such as lead or from paper, plastics or othersuitable materials.

In the foregoing embodiment, priming mix 11 is about 9/10 grain of amixture of aboutz35% potassiumchlorate, 17% lead sulfocyanate, 30%antimonysulde, k15%fcal-V cium silicide and 3% trinitrotoluene. togetherwithI about 1/10% gum tragacanth or other suitable binder.-Theparticular composition of the priming in the various embodi-r mentsis not critical, however, and conventional priming compositionscontaining potassium chlorate or other -suit. able oxidizer such as, forexample, potassium nitrate,v barium nitrate, lead peroxide, and thelike, with suitablel explosives, such as, lead styphnate, lead azide,tetrazene and the like can be utilized. Particles of glass orotherequivalent abrasive material should be used inrimre primers of the typeillustrated. as 211. Fuels y,Suchaspowdered aluminum and the 7like, canbe substituted for all or part kor' the antimony sulfidev and.A calciumsilicide In fact, any standard percussion` type .primer-suitable-foryigniting the propellant in conventional cartridgesfonshotguns or othersmall arms, orin stab-initiated-detonators,

is suitable. A primer containing normalr-and-sbasic leadV l styphnate,aluminum, antimonysulde and'barium nitrate is an example of a suitableprimer,for..the.embodiment illustrated in Figure 4.

The embodiments of Figures 2,v 3 and z4..are,-of.course, assembled withlengths of detonatingtfusewin:thesame manner .as the embodiment ofFigure 1.

Various yother well known explosives-.maybe :substituted for theexplosive charges 1, 3: and'4 shownl inthe. foregoing embodiments. Forexample, mercury fulminate, mixtures of mercury fulminate andpotassium'fchlorate,y diazodinitrophenol, tetryl, nitromannite and the-likemay be utilized in some embodiments alone'onin vmixtures thereof.Indeed, it is contemplated-that charges 1, 3A .and 4 may be replacedwith a single charge'of an exploL sive such as tetryl, cyclonite,nitromannite or trinitrotolueneor the like in some embodiments of thevinvention. The weight of the various explosive charges is not-critical,but it is preferred, that the assembly be at least equivalent instrength to a standard ,Bureau of Mines No.- f 6 detonator having acharge of one gram of.a,90-l0 mixture of mercury fulminate and potassiumchlorate. but good results can be obtainedif the assembly has a greaterpower than that of the Bureau of AMines detonator.

`Other suitable delaypowders maybesubstitutedfforv dely composition 5and the amount-used. willl vary-y withv the time interval required. -Inmost instances, however, a delay of from about 0.03 to about 0.05 secondwillbe. required in practice. magnesium, barium peroxide and selenium,barium permanganate and antimony, or charges of black powder and thelike may be utilized. 4In fact, many other knowngas-producingcompositions are suitable for the'purpose. f

Moreover, some delay betweenV the detonationy of the lengths of fusewillbe obtainedfrom the assembly ,even if no delay mix or detonatingcharge is included so suchy a device is within they purview of thisinvention.l In,thi s type of device not containing a delay mixheintervalMA betr/Sea detonatitms,sependem @months .,lfziigtltf.the..7

A blendof bariumiperoxide .and-

space between the firing pin, the depth of the crimp holding the ringpin in place and the distance between the primer and the detonatingfuse.

It is essential, for best results, that some space be provided betweenthe closed end of the lring pin and the detonating fuse. It has beenfound that, in the absence lof such space, `often no delay will beachieved between the ignition of the rst length of detonating fuse andthe ignition of the second length thereof. This space may be provided asshown in Figure 1 or the length of the firing pin may be suflcient toextend to the fuse. In `the latter embodiment, the required space isprovided within the firing pin. It is also necessary, for best results,that space be provided between the point of the tiring pin and theprimer assembly in order lto insure that the tiring pin will strike thecap with sulcient force to properly initiate the priming composition.`In embodiments adaptable for coupling commercially available detonatingfuse having a diameter of from about 0.2 to 0.225 inch, it is preferredthat the outside diameter of the tube 13 be about 0.267 inch and thatthe thickness of the sidewalls of tube 13 be about 0.017 inch. As statedabove such a tube can be conveniently about 4.5 inches long, althoughtubes of other dimensions can be utilized. In such a tube, space Z1 maybe about one inch, space 25 about 1/8 inch and `annular ring 17 may belocated 1%,- inch from the end of tube 13. Tube 13 may be made of anymaterial adapted to have indentations formed in the wall thereof. Forexample, it may be made of aluminum, copper, copperzinc alloys,synthetic resins, waterproofed paperboard or laminated paper or othersimilar materials.

The device provided by this invention is suitable for use with varioustypes of detonating fuse. It has been found most advantageous, however,for use with detonating fuse similar to that known to the trade asPrimacord. Such a detonating fuse has Ia core of high velocityexplosive, usually pentaerythritol tetranitrate, enclosed in an outercase of fabric or metal which may or may not be coated with awaterproofing material Such as a nitrocellulose base lacquer. Such afuse may detonate at a velocity in the neighborhood of 20,000 feet persecond.

Itis to be understood, of course, that although it is preferred forconvenience and ease of assembly topress the explosive charge, delaycomposition and percussion type igniter in a detonator case Such asdescribed in detail above, it is possible to position them in tube 13without use of the detonator case, provided the charges are properlypressed therein and, consequently, such a construction is contemplatedby this invention. In some instances, the ange at the mouth end of aconventional shotshell battery cup may be too large to lit properly inthe detonator case. Under Such conditions, it will be necessary to clipor otherwise trim the ange to the proper diameter to form a snug fitwithin the detonator case 2. It is also conceivable that ferr ule 6 maybe eliminated entirely and that the percussion type igniter can beproperly positioned in tube 13 or in the mouth of detonator 2 by othermeans such as by forming an annular groove in the wall of detonator case2 at a predetermined location such that the base of battery cup 9 willrest against it when properly located in the mouth of case 2. Althoughit is preferred, for the convenience of the user of the device, toinclude means for stopping the fuse before it contacts the ring pin, thering 17 or other means for stopping the fuse may be omitted from someembodiments provided care is taken by the operator to insert the fuse tothe proper depth.

Many other variations in details of assembly may be made by thoseskilled in the art without departing from the spirit of this inventionexcept as limited by the appended claims. While use of this device isprimarily advantageous in commercial blasting operations it is to beunderstood that it may be used in any type of operation wherein two ormore lengths of detonating fuse are to be initiated successively afterpredetermined delay periods.

What is claimed is.

1. A device for joining a i'irst length of detonating fuse to a secondlength of detonating fuse in end-to-end relationship and for retardingthe initiation of the second length of fuse a predetermined timeinterval after detonation of the first length of fuse, Said devicecomprising a tube adapted to be slipped over the adjacent ends of therst and second lengths of the detonating fuse, a tiring pin slidablymounted in said tube adjacent the end of the first length of detonatingfuse, an explosion retarding element within the tube having a primerpositioned between the tiring pin and the second length of fuse andspaced from the tiring pin, a delay composition in the tube in aposition to be activated by the primer and a detonating chargeinterposed between said delay compostion and the end of the second fuse,and means for confining the gases developed by the iirst length of fusebehind Said ring pin and for preventing movement of said pin at lessthan pressure suicient for driving the ring pin into Said primer with aninitiating force.

2. The device of claim 1 wherein said primer is a percussion cap.

3. The device of claim 1 wherein said primer is stab initiated.

References Cited in the tile of this patent y UNITED STATES PATENTS120,963

